EAGER: A mechanism for xylem embolism repair under tension

在植物中，水分运输系统（木质部）中的液压故障是由气泡的引入和单个传导细胞中栓塞的形成引起的。事实上，植物可以修复木质部栓塞，即使它们的液压系统处于相当大的张力下，仍然是植物科学中最令人困惑和最重要的奥秘之一-这种修复的机制基本上是未知的，尽管有证据表明这种现象发生在各种植物物种中。这项研究将测试一个新的假设，栓塞修复的物理机制在张力下。这项研究将在北美各地的野外进行。要进行的测量包括由于栓塞形成，根和茎木质部中的气体含量在现场和在实验室中的受控条件下，以及染料示踪剂和解剖学研究，以确定栓塞形成和修复过程中的水运动的途径的电导率损失的百分比。这项研究可能会对植物生物学产生变革性的影响，因为它建立了植物在输水细胞中存在丰富气体的情况下在高张力下维持水分运输的机制。拟议的活动将有助于资助博士学位。学生和博士后职位。 在加州州立大学富勒顿分校，该项目将包括本科生积极参与研究，包括大量来自代表性不足群体的学生。这项研究可能会对园艺和农业的应用产生影响，最直接的是木本水果作物的可持续灌溉管理实践。

In plants, hydraulic failure in the water transport system, the xylem, is caused by the introduction of gas bubbles and formation of embolisms in individual conducting cells. The fact that plants can repair xylem embolisms even when their hydraulic systems are under considerable tension has remained one of plant science's most puzzling and important mysteries - the mechanisms underlying this repair are essentially unknown despite evidence the phenomenon occurs in a wide variety of plant species. This research will test a novel hypothesis about a physical mechanism of embolism repair under tension. The research will be conducted with shrub species from field sites across North America. Measurements to be conducted include the percent loss of conductance due to embolism formation, gas contents in root and stem xylem in the field and under controlled conditions in the lab, as well as dye-tracer and anatomical studies to determine the pathways of water movement during embolism formation and repair. The research could potentially be transformative for plant biology by establishing mechanisms by which plants sustain water transport under high tension in the presence of abundant gas in their water transport cells. The proposed activity will help to fund a Ph.D. student and a postdoctoral position. At Cal State Fullerton, the project will include active involvement of undergraduate students in the research, including a large number of students from underrepresented groups. The research potentially will have implications for application in horticulture and agriculture, most directly for sustainable irrigation management practices of woody fruit crops.